In which process is pyruvate conve m ei yh3zabvcgk0 3e;52i/x,vrted to acetyl CoA?

  Which pair of characteristics are correct descri/nyf 3d :s(ojx7 qmx+g b)gc2hptions of aerobic and anaerobic cellular respiratio sgcgh3fx j:y+ d(bm)2q7/nxon?

  In chemiosmosis, what is the name of the enzyme we,g9hjtao1ik- ./zywhich plays an important role in az9je.kw/1ti y,hg-o the diffusion of protons into the matrix of the mitochondrion?

  What happens after the oxidative dec+ce0y):nq q hrarboxylation of pyruvate?

  What are the products of the hydrolysis o e),p3pax)pbge.l 6k vf ATP?

  Which of the following diagrams shows the correct structurewlmf+6e6 ohs x.zl(r* of ATP?

  Which of the following processes does not require ey(*n5cm f-vi.emr,: goqyg+rnergy from ATP?

  Which of the following requires ATP as an immediate s2(v+ooaav h+; dxzb)o ource of energy?
I.Transmission of a nerve impulse
II.Osmosis
III.Condensation of a polypeptide

  Which substance is present in the m2e)yn u0dob ;brewing of beer but not found in bread?

  How many times does phospqj8 mr: kw-/lsysu/4 khorylation happen in glycolysis?

  In respiration which process does not involve the conversion s tdra)8 jys,vzu4e-; of ADP to ATP?

  There are four main stages of respiratiqsuozlb (; 0,ion.
Identify the correct row in the table below that is true of these four stages.

There are four stages in cellular respiration. Some of these st - odp2-ttri 2kr-*tlu*ua;x nages take place in the mitochondria. The electron micrograph shows an image of a mitochondrion from a mouse embryonic fibroblast ;p*da lut txi2 kr2rt- n-*uo-(MEF) cell.

1.Label the diagram with the letter A to indicate the location of ATP synthase.
2.ATP is the energy carrier that provides an immediate source of energy to the cell. State one more energy carrier in cellular respiration other than ATP.
3.Outline the roles of oxidation reactions in oxidative phosphorylation.
4.Explain what would happen to the cell if cellular respiration was an uncontrolled release of energy from glucose.

  The diagram shows part of the electron transport chain. 28e s7nfxo/fc

What explains the role of oxygen?

Coleus blumei is an attractive house8z+ 5jsib( ,zw5im6+bjsp rzpplant with red leaves.


1.Determine with a reason whether or not this plant is still able to conduct photosynthesis with red leaves.
2.Red leaves absorb and reflect different coloured light than green leaves. Distinguish between red light and green light in the visible spectrum.
3.Outline how limiting factors affect the rate of photosynthesis.
4.Explain how oxygen produced during photosynthesis can be used during respiration.

  Which of the following processes in2ngde: geo7(snl7 dc8volve decarboxylation?
I.Phosphorylation of glucose
II.Oxidation of pyruvate to form acetyl CoA
III. Oxidation of an acetate group to reform the four-carbon oxaloacetate

  The Krebs cycle is one of the stages in aerobic cellular respiration i+/p;hgx m*qh1sr/ te. Which of the following correctly desc+1hpxeqm*hgs i r/;/tribes the electron carriers?

  Which of the following evx a0m0w: oo -+ao.vvxb (jqw3+dp (ncorrectly describes photosynthesis or respiration?

  A mitochondrion is shown in the diagram. Which letter indicates the site whasw til+ uk621we/v bfpv1x5 0ere protons accul/fsuw 6ti10v 5xkv+e 12wbapmulate prior to the formation of ATP?

  The graph shows the chajaq +0sk) cytx,,0bpy5hg8ns nges in blood pH levels of an individual before exercise, 8sj)cbnqy sh0pt+ gy,a5 0,xk during exercise and after exercise.


Which statement may explain the changes in blood pH shown in the graph?

Cell respiration is a metaboq 7tc. 6t*nrrkoh( c5vlic process that occurs in living organisms.
The electron micrograph shows a longitudinal section of a budding yeast cell.


1.ATP is a readily available source of energy for a cell. The primary substrate for the production of ATP is glucose. State one more possible substrate other than glucose.
2.Identify the part of the yeast cell labelled A in the image.
3.The ability of yeast to produce carbon dioxide is used in the making of food and beverages. Outline the role of carbon dioxide in the making of bread.
4.Discuss which type of respiration is adapted for high-intensity activities such as weightlifting and sprinting.

  Below is a micrograph of mitochondria with four structures or locatw gg4//q m6ptiions labelled. Which is a correct description of how one of t qm6/gi wgt4/phese structures is adapted to its function?

Oxidative phosphorylv go t81x/2uqnmy.vv 9ation, which generates ATP for the cell, is comprised of the elq.8nu g2t/v ym1 x9ovvectron transport chain and chemiosmosis.
1.Distinguish between the electron transport chain in aerobic cellular respiration and the electron transport chain in photosynthesis.
2.Outline how ATP can be recycled after being used by the cell.
3.Explain how 38 molecules of ATP can be produced from one glucose molecule in a cell.

  Human mesenchymal stem cells (MSCs) are found in a variety of tissue ta(-gnn ge0e4s, such as the bone marrow and adipn gt0 na4eg(-eose tissue. Due to their multipotency, MCSs can differentiate into a number of different types of cell.
Recent studies have suggested that changes in metabolism are vitally important during the process of cell differentiation. In one such study, scientists investigated the changes which occur to the mitochondria in MSCs during the process of differentiation into adipogenic cells, which are cells of the adipose tissue, an important energy storage site in the body.
To begin the investigation, scientists had to stimulate the differentiation of MSCs into adipogenic cells. Differentiation of MSCs was confirmed with the use of both Oil Red O staining and RT-PCR, which demonstrated the relative expression of adiponectin mRNA, which is a key indicator of adipogenic differentiation.


1. 1.Calculate how many times greater the expression of adiponectin is in adipogenic cells after 21 days, compared to 7 days.  
2.Predict the relative expression of adiponectin mRNA after 14 days. `  

In their next experiment, scientists stained mitochondria in undifferentiated MSCs and differentiated adipogenic cells after 7 days, using MitoTracker Green stains, and then using flow cytometry, recorded fluorescence as a measure of mitochondrial mass.

2. 1.Suggest why there is an increase in mitochondrial mass in adipogenic cells after 7 days compared to MSCs.
2.Calculate, as a percentage, the increase in mean fluorescent intensity in adipogenic cells after 7 days compared to MSCs.  %

In their penultimate experiment, scientists measured the TOM20 protein levels of the outer mitochondrial membrane.


3.Compare and contrast the results obtained from the measurement of mitochondrial mass using flow cytometry and protein levels.

In their final experiment, scientists measured the mitochondrial oxygen consumption rate and lactate production in both MSCs and adipogenic cells.

4. 1.Outline the effect of differentiation on the rate of oxygen consumption and lactate production.
2.Suggest a reason for the change in oxygen consumption rate in adipogenic cells from day 1 to 7.
3.Explain, with reference to respiration, the change in lactate production in adipogenic cells.
5.Explain how the results obtained from these experiments on mitochondria can be used to understand metabolic changes during differentiation.
6.Using all the data provided, evaluate the hypothesis that the rate of respiration increases during cell differentiation

DNA and RNA are nucleic acids that are essential t*0in/ b 2lb;pk* j hoy0qyv 3uhxzea2(o all living organisms.
1.Distinguish between ATP and DNA.
2.Discuss model-making as an approach used in the discovery of the structure of DNA and the importance of this discovery.
3.DNA is a polymer of nucleotides. Describe the structure of DNA.

  Students were investigating metabolic reactions in the classroom and werfdh5 :1r.sea+mwbo o; e given an experiment which demonstrated the effect of temperature on a catabolic re .ear:1 ;fb5o +omdwhsaction.
A sample of fat was added to a beaker, which contained 150ml of a 1% sodium chloride solution.



The beaker and its contents were then added to a water bath, which was set at 15
o
C. The beaker was given 5 minutes to equalise with the temperature of the water bath. After 5 minutes,5 ml of a 2% lipase solution, at the same temperature as the water bath, was added to the beaker.


5 ml of 2 % sodium hydroxide (NaOH), pH 8.4, was added to a test tube and phenolphthalein, a colourless solution which turns pink in basic environments, was then added. The intensity of the pink colour is proportionate to the strength of the basic solution.
At exactly 20 minutes, a 5ml sample was taken from the beaker incubated in the water bath and added to the test tube.


The contents of the test tube were then immediately transferred into a cuvette and placed in a spectrophotometer set at 420 nm. The percentage transmission of light able to pass through the sample was measured and recorded.


The procedure was then repeated using water baths set at a range of different temperatures. The measurements were recorded in a table and presented in a graph.



1. 1.State the independent variable in this experiment.
2.Identify two factors, not already mentioned, that would need to be controlled in this experiment.
2. 1.Explain how the spectrophotometer is able to measure the breakdown of fat.
2.Explain the effect of increasing the temperature from 15
o
C to 35
o
C on the rate of the catabolic reaction.
3.Predict the percentage transmission for a sample incubated at 20
o
C.  %
4.Evaluate the claim that based on the data, the optimum temperature for lipase activity is 35
o
C.

  The graph shows the amount of oxygen inside a chamber containing yeast cells az,ck6sxgr (n- ), +z6jso (szmmlw2fpnd substrates as measured by an oxygen sensor. The experimental investigation compared tk zmz,xr-+mzc)gs, (6o2fpj s 6sn (lwhe rate of oxygen consumption during aerobic respiration by the yeast cells using three different substrates: sucrose, fructose and glucose.


What can be concluded from the graph?

Cancer studies have shown that many tumours have abnormal patternid: vlouo7df5.* fp z.6kd ,wrs of aerobic respiration, showing increased levels of glycolysis and lower levels of oxidative phosphorylation, ev.fd 7fi, 5*vdo:zk pdlu.6owren in the presence of high oxygen levels. A breast cancer cell line (MDA-MB-231) shows variable protein expression of complex III in the electron transport chain compared to normal breast tissue.



1.State the independent variable in this study.
2.Outline the role of the complexes in the electron transport chain.
3.Suggest one advantage and one disadvantage of breast cancer cells using glycolysis to generate ATP rather than oxidative phosphorylation.
4.Predict, with a reason, what would happen to the levels of oxidative phosphorylation in the non-cancerous cells if they were treated with an inhibitor of glycolysis.
5.Explain why non-cancerous breast cancer cells were used as a control in this study.
6.The researchers concluded that downregulation of complex III in breast cancer cells is a cause of breast cancer. Evaluate this conclusion.
7.Outline one measurement that could be taken to determine the activity of Complex III in this study.

Mitochondria are known as the powerhouse of the cell because they produca8r,+yrin1ocn h+hd5 e a high yield of adenosine triphosphate (ATP) through cell respirr+n ind+ hy15oh8car,ation. Large numbers of mitochondria can be found in muscle cells.
1.Distinguish between anaerobic respiration in muscle and yeast cells.
2.Outline the role of ATP in cells.
3.Explain how the rate of cellular respiration can be measured.

  The graph below shows the chan 8dmufirfbc uk5c5l: 0t4k06mges in the levels of lactate on the skin of athletes during pre-training (rest), training, and rekd0lfk65f5tmum r 84i0cb:uc covery.

Based on the graph, which is true?

  Which statement(s) are correct in explaining why lipids are :q dvs1*n5* p(denzzg y2qh4kused as a long-term energy store insq2kzh *q:np5neg(d 1y* z4vdstead of carbohydrates?

I.Lipids contain more energy per gramme than carbohydrates
II.Lipids are insoluble, whereas carbohydrates are not
III.Lipids contain less oxygen than carbohydrates

  A respirometer is a device that can be used toeqven hq9;9aa8 5ki4 zut*j 2v measure the respiration rate of germinating s4nji ku aqat9z2v5e; v q89he*eeds.


In the experimental set-up shown above, how is the rate of oxygen uptake measured?